THE ABBREVIATED INJURY SCALE AS A PREDICTOR OF OUTCOME OF SEVERE HEAD-INJURY

Objective: This study examined the correlation between the worst abbre viated injury scale 1990 (AIS) intracranial severity score and outcome following severe head injury. Design: The initial CT scans of 109 sev erely head injury patients were examined by a neuroradiologist and cla ssified according to the worst applicable intracranial severity code f rom the AIS. This score was then correlated with the glasgow outcome s cale (GOS) at 6 months. For comparison, the GOS was also correlated wi th the diffuse injury scale (DIS) described by L.F. Marshall et al. [5 ], the worst post-resuscitation Glasgow coma score (GCS) in the first 24 h, and the head injury outcome prediction tree described by Choi et al. [1]. Results: Our results show Spearman rank correlation coeffici ents of 0.58 (p < 0.001), 0.47 (p < 0.001), 0.45 (p < 0.001), and 0.31 (p < 0.01) for the correlation between the AIS, prediction tree, DIS, and GCS respectively and the GOS. Independent outcome (i.e. GOS good or moderate) was strongly predicted by an AIS of 3 or less (positive p redictive value 95%, specificity 98%, sensitivity 40%, likelihood rati o 25:1). Death or vegetative survival was less strongly predicted in p atients with an AIS of 5 (positive predictive value 71%, specificity 7 5%, sensitivity 67%, likelihood ratio 2.7:1). Conclusion: The AIS, bas ed on initial CT scan, provides useful prognostic information in patie nts with severe head injury.